CVE-2026-30851

Name: CVE-2026-30851
Creator: NVD / NIST
Published: 2026-03-07T17:15:52.54+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2026-30851 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Caddy is an extensible server platform that uses TLS by default. From version 2.10.0 to before version 2.11.2, forward_auth copy_headers does not strip client-supplied headers, allowing identity injection and privilege escalation. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

Description

Caddy is an extensible server platform that uses TLS by default. From version 2.10.0 to before version 2.11.2, forward_auth copy_headers does not strip client-supplied headers, allowing identity injection and privilege escalation. This issue has been patched in version 2.11.2.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.25%

16.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Caddyserver	Caddy	>= 2.10.0, < 2.11.2

References

https://github.com/caddyserver/caddy/issues/6610Issue Tracking
https://github.com/caddyserver/caddy/pull/6608Issue Tracking, Patch
https://github.com/caddyserver/caddy/pull/7545Issue Tracking, Patch
https://github.com/caddyserver/caddy/security/advisories/GHSA-7r4p-vjf4-gxv4Exploit, Mitigation, Patch, Vendor Advisory

Timeline

Published: Mar 7, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-30851?

How severe is CVE-2026-30851?

CVE-2026-30851 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-30851?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-30851?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST